If your workplace uses chemicals, cleaning products, gases, dusts, fumes or other hazardous substances, the Control of Substances Hazardous to Health Regulations — commonly known as COSHH — may apply.
But what exactly is COSHH, what does it cover and what do employers need to do?
COSHH stands for the Control of Substances Hazardous to Health. The COSHH Regulations require employers to assess risks from substances that could cause ill health at work and take appropriate steps to prevent or adequately control exposure.
COSHH can apply to chemicals, cleaning products, dusts, fumes, gases, vapours, mists and biological agents, as well as hazardous substances created by workplace processes.
The Health and Safety Executive's COSHH guidance provides official guidance for employers on managing hazardous substances at work.
COSHH covers many substances that could be hazardous to health, including:
Importantly, COSHH isn't limited to substances supplied in containers with hazard labels.
Workplace processes can also create hazardous substances, including:
Employers therefore need to consider both the products they use and the hazardous substances their work activities may generate.
The HSE provides further guidance on substances hazardous to health.
Some hazardous substances are subject to separate regulations. COSHH does not cover lead, asbestos or radioactive substances.
The Control of Substances Hazardous to Health Regulations 2002 set out requirements for protecting people from substances hazardous to health at work.
In general, employers need to:
The controls required will depend on the substance, work activity, potential exposure and people who could be affected.
A COSHH assessment identifies the risks associated with substances hazardous to health and determines what measures are needed to prevent or adequately control exposure.
It should consider the substance in the context of the actual work activity, rather than simply copying information from a safety data sheet.
For example, a cleaning chemical used occasionally in small quantities may present different risks from the same product being sprayed regularly in a poorly ventilated area.
The HSE provides official guidance on how to carry out a COSHH risk assessment.
No. A safety data sheet (SDS) provides useful information about a chemical, including its hazards, handling, storage and emergency measures, but it isn't a COSHH assessment.
The information in an SDS can help inform the assessment, but employers also need to consider how the substance is actually used, who could be exposed and whether workplace controls are adequate.
See the HSE's guidance on chemical safety data sheets.
A COSHH assessment should consider the following areas.
Identify hazardous products and any hazardous substances generated by work activities. Gather relevant information, including safety data sheets where applicable.
Determine what harm could result from exposure. Depending on the substance, this could include skin or eye irritation, dermatitis, respiratory problems, sensitisation, organ damage or longer-term health effects.
Consider everyone who could be affected, including:
Potential routes of exposure include:
The assessment should consider how frequently the substance is used, how much is used and how exposure could occur during the actual task.
Identify measures already being used to prevent or control exposure.
These could include:
Where existing controls aren't sufficient, additional measures should be introduced. The focus should generally be on preventing or controlling exposure rather than relying solely on PPE.
Depending on the substance and level of risk, employers may also need to consider exposure monitoring or health surveillance.
Some hazardous substances have Workplace Exposure Limits (WELs). The HSE publishes these in EH40 and provides further guidance on Workplace Exposure Limits.
Relevant findings and controls should be communicated to the people affected.
Assessments also need to remain current and should be reviewed when relevant circumstances change.
The responsibility for managing risks under COSHH generally sits with the employer, although completing an assessment can be delegated to someone with appropriate knowledge, skills and experience.
The person carrying out the assessment should understand:
A COSHH assessment shouldn't simply be treated as a paperwork exercise. It should reflect what actually happens in the workplace.
Organisations that don't have the appropriate expertise or resources in-house may choose to seek competent external support like Spiers Engineering Safety to help them with assessing hazardous substances and managing workplace exposure risks.
Where COSHH applies, employers are legally required to assess the risks associated with substances hazardous to health and take appropriate steps to prevent or control exposure.
The legal requirements are set out in the Control of Substances Hazardous to Health Regulations 2002.
However, producing a COSHH assessment document alone doesn't make a workplace compliant. Appropriate controls need to be implemented, maintained and used effectively.
There isn't a universal rule requiring every COSHH assessment to be reviewed at exactly the same interval.
An assessment should be reviewed when circumstances change or there is reason to believe the existing assessment may no longer be valid.
This could include when:
Regular internal reviews can also help organisations ensure their assessments remain accurate and useful.
A COSHH assessment is a specific type of risk assessment focused on substances hazardous to health.
A general workplace risk assessment might consider hazards such as machinery, working at height, manual handling, workplace transport or slips and trips.
A COSHH assessment specifically considers hazardous substances, potential exposure and the measures required to control that exposure.
An organisation may therefore have COSHH assessments alongside many other types of workplace risk assessment.
Failing to properly control exposure to hazardous substances can put workers at risk of occupational ill health.
It can also result in regulatory enforcement where legal requirements aren't being met.
Poor management of hazardous substances can contribute to:
The most important reason for managing COSHH effectively is to prevent people becoming ill because of their work.
When completing or reviewing a COSHH assessment, ask:
Managing a small number of COSHH assessments may be relatively straightforward.
As the number of substances, employees, sites and assessments grows, however, it can become increasingly difficult to maintain visibility.
Organisations relying on spreadsheets, Word documents, shared drives or paper assessments may find it harder to answer questions such as:
A centralised system can make it easier to organise assessments, monitor outstanding actions and keep track of upcoming reviews.
RiskMach helps organisations manage workplace risk assessments and safety information digitally.
Rather than relying on disconnected documents or spreadsheets, teams can use a central system to manage assessments, actions and reviews.
For organisations managing numerous COSHH assessments, this can provide clearer visibility over what has been assessed, what requires attention and when assessments need to be reviewed.
Not necessarily as a separate document for every chemical. Employers need to assess risks from substances hazardous to health based on the hazards, potential exposure and how substances are actually used or produced at work.
Potentially, yes. Some cleaning products contain substances that can be hazardous to health. The risks and controls required will depend on the product and how it is used.
Yes. Certain workplace dusts can be hazardous to health, including dust generated by work activities such as cutting or sanding.
Yes. Welding can generate fumes hazardous to health, so employers need to consider the risks and appropriate controls.
COSHH can apply to self-employed people depending on the nature of their work and associated risks.
No. COSHH and REACH deal with different but related aspects of chemical safety. COSHH is primarily concerned with controlling exposure to substances hazardous to health in the workplace.
There isn't a universal expiry period for COSHH assessments. They should be kept up to date and reviewed when relevant circumstances change or when there is reason to believe an existing assessment is no longer valid.
COSHH is about preventing or adequately controlling exposure to substances that could damage people's health at work.
Effective COSHH management involves identifying hazardous substances, understanding how people could be exposed, assessing the risks, implementing appropriate controls and keeping those controls and assessments up to date.
A COSHH assessment should therefore be a practical tool for managing workplace risk rather than simply a document stored for compliance purposes.
For organisations managing large numbers of assessments, sites or actions, a centralised digital system can also make it easier to keep track of what has been assessed, what needs attention and when reviews are due.